Digital magnetic recording/reproducing apparatus and cassette digital magnetic recording/reproducing apparatus

ABSTRACT

A digital magnetic recording/reproducing apparatus comprising a unit for recording high-definition information including video information and audio information, which is based on a first high-definition television scheme, on a recording medium in accordance with a second high-definition television scheme, the first high-definition television scheme having a first data format of a first amount of information smaller than a second amount of information of a second data format of the second high-definition television scheme, the recording unit including a circuit for allocating a recording area corresponding to a difference between the first amount of information and the second amount of information as a free recording area on which any information is selectively recorded, to match the first amount of information with the second amount of information.

This application is a Continuation of application Ser. No. 08/214,768,filed on Mar. 18, 1994, now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a digital magneticrecording/reproducing apparatus for recording/reproducing a plurality ofdifferent television standard signals and, more particularly, to acassette digital magnetic recording/reproducing apparatus capable ofcoping with the HDTV schemes used in Japan, the United States, andEurope.

2. Description of the Related Art

Japan is a leading country in test broadcasting of an HDTV scheme forproviding an image having a definition higher than that of a currentlyused television scheme.

The Japanese HDTV scheme is called a "high-vision" scheme in Japan. Inthis HDTV scheme, the number of scanning lines was defined as 1,125, anda field frequency was defined as 60 Hz.

On the other hand, Europe and the United States plan to employ HDTVschemes different from the Japanese HDTV scheme. An HDTV scheme having1,250 scanning lines and a field frequency of 50 Hz is probably employedin Europe, and an HDTV scheme having 1,050 scanning lines and a fieldfrequency of 59.94 Hz is probably employed in the United States.

As described above, when machines for producing or transmitting programsare different from each other in the television schemes, respectively,machines corresponding to these schemes must be developed andmanufactured. For this reason, costs naturally increase. In addition, ina given television scheme, in order to reproduce software produced in ascheme different from the given scheme, a VTR or telecine suitable forthe given scheme must be prepared. Signal conversion is performed by aformat change apparatus, and then the software is recorded again. Forthis reason, trouble and costs increase.

A VTR is one of principal machines used when programs are produced ortransmitted, and a VTR used for broadcasting is generally expensive. Forthis reason, if a tape transport, a signal processing circuit, acassette, and a tape are commonly used in different HDTV schemes, thecosts of machines and running costs are reduced, thereby obtainingadvantages for users. In addition, if tapes recorded in differentschemes can be reproduced in the same VTR, programs can beadvantageously, easily exchanged to each other between differentcountries at a low cost.

However, in a conventional magnetic recording/reproducing apparatus,high-definition images respectively recorded in different HDTV schemescannot be recorded/reproduced using a common mechanism. Moreover, thereis no apparatus for performing digital recording to a cassette tape.

SUMMARY OF THE INVENTION

The present invention has been made in consideration of the aboveproblems, and has as its object to provide a cassette digital magneticrecording/reproducing apparatus for recording/reproducing signals ofdifferent HDTV schemes using the same mechanism, the same cassette, andthe same tape.

According to the present invention, there is provided a digital magneticrecording/reproducing apparatus comprising:

means for recording high-definition information including videoinformation and audio information, which is based on a firsthigh-definition television scheme, on a recording medium in accordancewith a second high-definition television scheme, the firsthigh-definition television scheme having a first data format of a firstamount of information smaller than a second amount of information of asecond data format of the second high-definition television scheme, saidrecording means including means for allocating a recording areacorresponding to a difference between the first amount of informationand the second amount of information as a free recording area on whichany information is selectively recorded, to match the first amount ofinformation with the second amount of information; and

means for reproducing the high-definition information recorded on therecording medium.

As a means for identifying different schemes when a common cassette isinserted, there is provided a cassette digital magneticrecording/reproducing apparatus in which a cassette is inserted into acasing, high-definition information consisting of video information andaudio information is recorded/reproduced on/from a magnetic recordingmedium in the cassette in accordance with identification information,attached to a casing of the cassette, for identifying a plurality ofrecording/reproducing methods for the recording medium, comprisingidentification information reading means for slidably reading theidentification information arranged on the casing of the cassette, andrecording/reproducing method selection means for selecting one type ofrecording/reproducing method from the recording/reproducing methods inaccordance with identification information read by the identificationreading means, wherein a reading operation of the identificationinformation reading means is performed when the cassette is insertedinto the casing.

As a means for identifying different schemes in a tape reproducingoperation or in a switching operation from a fast-forward operation to arewinding operation, there is provided a digital magneticrecording/reproducing apparatus for recording/reproducinghigh-definition information consisting of video information and audioinformation on/from a magnetic recording medium in accordance with afirst recording/reproducing method of recording/reproducing thehigh-definition information having an information amount of A (A>0) bitsand a second recording/reproducing method of recording/reproducing thehigh-definition information having an information amount of B (B>A)bits, comprising identification information recording means forrecording/reproducing method identification information for selectingone of the first recording/reproducing method and the secondrecording/reproducing method as a method of recording/reproducing thehigh-definition information, identification information reproducingmeans for reproducing identification information recorded by theidentification information recording means, recording/reproducing meansfor performing recording/reproducing operations using the firstrecording/reproducing method or the second recording/reproducing methodin accordance with the identification information reproduced by theidentification information reproducing means, wherein the identificationrecording/reproducing means records the recording/reproducing methodidentification information on the magnetic recording medium.

According to the present invention, the information amount of a Japanese1125/60 HDTV video signal is larger than that of an European 1250/50HDTV video signal or a U.S. 1050/59.94 HDTV video signal. For thisreason, when data of the 1125/60 scheme is recorded using a singlerecording/reproducing mechanism and a single format on a tape, therecording area for the data is redundant in the 1250/50 scheme or the1050/59.94 scheme. For this reason, another effective signal is recordedin this redundant area. In addition, an HDTV signal has a largeinformation amount, a 1-field HDTV signal is divided and recorded on aplurality of tracks. At this time, an audio signal is recordedtime-divisionally such that AUDIO information per field can beindependently edited later in the tracks in which the 1-field videoinformation is to be recorded.

Although an editing operation is performed in units of frames or fields,tracks located boundary portions between the frames or the fields areeasily damaged by an mechanism error, defective tracking, or the like.In particular, degradation of an audio signal is easily detected.Therefore, a normal audio signal is not recorded on only the trackslocated at the boundary portions between the frames or fields, blanktracks are formed, or another information signal is recorded on thesetracks, thereby preventing problems in the editing operation.

When a common cassette is used in recording/reproducing operations ofdifferent schemes, and the cassette is inserted into a VTR, it ispreferable to automatically identify the scheme of the cassette.According to the present invention, scheme identification informationarranged on the casing of the cassette is read by an identificationinformation reading means when the cassette is inserted, and anappropriate recording/reproducing method can be selected by arecording/reproducing method selection means. In this manner, since therecording/reproducing scheme can be quickly detected, subsequent systemsettings can be quickly performed.

Signals of different schemes can also be recorded on the same cassettetape. In this case, identification using a cassette is not performed,identification information is recorded on the tape using anidentification information recording means. In a reproducing operation,a recording/reproducing means is switched in accordance withidentification information from an identification informationreproducing means for determining one of the HDTV schemes, therebyappropriately reproducing the signals of the different schemes. Inaddition, when the identification information arranged on the casing ofthe cassette is erroneously set, the scheme can be quickly identified inreproducing the tape or in a fast-forward operation or a rewindingoperation, by recording identification information on the tape.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram according to the first embodiment of thepresent invention;

FIG. 2 is a view showing a track arrangement on a tape according to thepresent invention;

FIG. 3 shows views of a 1-frame Japanese scheme HDTV signal to berecorded;

FIG. 4 is a view showing data arrangements on tracks using the scheme inFIG. 3;

FIG. 5 shows views of a 1-frame European scheme video signal;

FIG. 6 is data arrangements on tracks using the scheme in FIG. 5;

FIG. 7 shows views of a 1-frame U.S. scheme video signal;

FIG. 8 is a view showing data arrangements on tracks using the scheme inFIG. 7;

FIG. 9 is a view showing a 1-field track pattern according to the secondembodiment of the present invention;

FIG. 10 is an enlarged view showing audio recording areas of a channelin FIG. 9;

FIG. 11 shows first views of various audio recording schemes;

FIG. 12 shows second views of various audio recording schemes;

FIG. 13 shows third views of various audio recording schemes;

FIG. 14 shows fourth views of various audio recording schemes;

FIG. 15 shows views showing recording data per field according to anembodiment of the present invention;

FIG. 16 is a view showing an error correction matrix according to theembodiment in FIG. 15;

FIG. 17 shows views of 1-field data arrangements according to theembodiment in FIG. 15;

FIG. 18 shows views of assignment of addresses on a field memoryaccording to the embodiment in FIG. 15;

FIG. 19 is a view showing the arrangement of an error correction circuitaccording to the embodiment in FIG. 15;

FIG. 20 is a view showing control of a normal reproducing field memoryaccording to the embodiment in FIG. 15;

FIG. 21 is a view showing control of a reproducing field memory when areproducing operation is performed in different schemes according to theembodiment in FIG. 15;

FIG. 22 is a view showing control of a reproducing field memory when areproducing operation is performed in different schemes according to theembodiment in FIG. 15;

FIG. 23 is a view showing control of a reproducing field memory when areproducing operation is performed in different schemes according to theembodiment in FIG. 15;

FIG. 24 is a block diagram showing scanning line identificationaccording to the fourth embodiment of the present invention;

FIG. 25 is a block diagram showing scanning line identification using abar-code label according to the embodiment in FIG. 24;

FIG. 26 is a block diagram showing scanning line identification using amagnetic card according to the embodiment in FIG. 24;

FIG. 27 is a block diagram showing scanning line identification using anoptical card according to the embodiment in FIG. 24;

FIG. 28 is a block diagram showing scanning line identification using amemory card according to the embodiment in FIG. 24;

FIG. 29 shows block diagrams of scanning line identification using aselection switch according to the embodiment in FIG. 24;

FIG. 30 shows views of the structures of selection switches according tothe embodiment in FIG. 24;

FIG. 31 is a block diagram showing a liquid crystal display according tothe embodiment in FIG. 24;

FIG. 32 is a block diagram showing audio display according to theembodiment in FIG. 24;

FIG. 33 is a block diagram showing scanning line identification using acue track according to the fifth embodiment of the present invention;

FIG. 34 shows views of signals of an oscillation circuit related to FIG.33;

FIG. 35 is a block diagram showing a first TC/CTL/CUErecording/reproducing circuit according to the embodiment of the presentinvention;

FIG. 36 shows signal waveforms of the recording system in FIG. 35;

FIG. 37 is a block diagram showing a second TC/CTL/CUErecording/reproducing circuit according to the embodiment of the presentinvention;

FIG. 38 shows main waveforms in FIG. 37;

FIG. 39 is a block diagram showing a third TC/CTL/CUErecording/reproducing circuit according the embodiment of the presentinvention;

FIG. 40 shows main pulse strings in FIG. 39;

FIG. 41 is an arrangement of a first segment signal according to anembodiment of the present invention;

FIG. 42 is a block diagram showing a first standard identificationcircuit according to an embodiment of the present invention;

FIG. 43 shows arrangements of second segment signals according to anembodiment of the present invention;

FIG. 44 is a block diagram showing a second standard identificationcircuit according to an embodiment of the present invention;

FIG. 45 shows arrangements of a third segment signal according to anembodiment of the present invention;

FIG. 46 is a block diagram showing a third standard identificationcircuit according to an embodiment of the present invention;

FIG. 47 is a block diagram showing a modification of the third standardidentification circuit in FIG. 46;

FIG. 48 is a first block diagram showing an arrangement in which areproduced image and a reproduced sound are not output when tapesrecorded in different standards are reproduced according to anembodiment of the present invention;

FIG. 49 is a second block diagram showing an arrangement in which areproduced image and a reproduced sound are not output when tapesrecorded in different standards are reproduced according to anembodiment of the present invention; and

FIG. 50 is a block diagram showing an arrangement in which states forcoping with standards are managed and determined according to anembodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The first embodiment will be described below with reference to FIG. 1.

FIG. 1 is a block diagram showing a digital VTR forrecording/reproducing an HDTV signal. Sixteen recording heads 12,sixteen reproducing heads 13, and an erase head (not shown) are arrangedon a rotary drum 11. In addition, recording amplifiers 14 for supplyinga current to the recording heads and reproducing preamplifiers 15 foramplifying signals from the reproducing heads are arranged on the rotarydrum 11.

A tape 17 in a cassette 16 is drawn from a supply reel 18 and wound onthe rotary drum 11 within the range of almost 180×, and then wound by atake-up reel 9.

During recording/reproducing operations, the tape 17 is transferred at apredetermined speed by rotation of a capstan 110.

In order to record/reproduce a cue audio signal, a time code signal, acontrol track signal, an erase head 112 and a recording/reproducing head111 are arranged on a tape transport.

Analog component HDTV signals from an external circuit are connected tovideo input terminals 113 to 115 of the VTR. A reference sync signal(SYNC) is connected to an input terminal 116, and an analog audio signal(8 channels) is connected to an input terminal 117. In this case,although analog input and output signals are exemplified, the VTR can beconnected to an external machine with digital signals as a matter ofcourse.

An input component video signal is converted into a digital signal byA/D converter 118/120, and an effective image is extracted by aneffective image extractor 121 (to be described later) and supplied to anECC encoder 122. An AUDIO signal 117 is converted into a digital signalby an A/D converter 123, is subjected to encoding unique to an audiosignal by an AUDIO encoder 124, and is supplied to the ECC encoder 122.On the other hand, the SyNC signal is supplied to a timing pulsegenerator 126 through a switch 125, and a timing pulse required forsignal processing is generated by the timing pulse generator 126. The SW125 selects a SYNC signal added to a normal input video signal in arecording or editing operation, and the SW 125 selects an externalreference sync signal (SYNC) in a reproducing operation.

The ECC encoder 122 performs error correction coding for correcting acode error occurring in recording/reproducing processes, and performsencoding for recording ancillary data supplied from an ancillary datagenerator 127 with video or audio data. Data output from the ECC encoder122 consists of 8-channel data corresponding to the recording heads, andthe data is digitally modulated by a modulator 128 into a signalsuitable for recording. Thereafter, a sync signal or an address signalgenerated by a SYNC information generator 130 is added to the modulatedsignal, and the resultant data is supplied to the recording amplifiers14 on the rotary drum through a rotary transformer (not shown).

In addition to recording/reproducing operations, operations such as afast-forward operation and a rewinding operation, an operation for theancillary data, a setting operation and the like of a time code or thelike, can be performed with a control panel 131 arranged on the frontsurface of the VTR. A control circuit 132 supplies a control signal to acircuit requiring the control signal in accordance with the contents ofoperations performed by an operator.

On the other hand, when a signal recorded on a tape is to be reproduced,a signal read by the reproducing heads 13 is amplified by thepreamplifiers 15 and supplied to an equalizer/detector circuit 133through a rotary transformer (not shown). After distortion received inthe recording/reproducing processes is compensated by the equalizer,binary digital data is detected by the detector. A sync detector 134detects sync information in the digital data, also supplies the syncinformation to a demodulator 135, and supplies the sync information toan ECC decoder 136 as a timing reference of a reproduced signal. Thedemodulator 135 performs an operation reverse to the operation of themodulator 128 to convert the recorded data into an information signal.The ECC decoder 136 corrects an error of the information signal, andseparately reconstructs a video information signal, an AUDIO informationsignal, and ancillary information signal. After the AUDIO signal isdecoded by an AUDIO decoder 137 in a manner unique to an AUDIO signal,the AUDIO signal is converted into an analog signal by a D/A converter138 and output from an output terminal 139.

After sync information or the like is added to the video signal by avideo information generator 140, the video signal is converted intoanalog signals by D/A converters 141 to 143 and externally outputthrough output terminals 144 to 146.

Character information or the like is added to the signals from the D/Aconverters 141 to 143 through a character generator 147, and theresultant signals are connected to a monitor 151 through monitor outputterminals 148 to 150.

On the other hand, ancillary information is decoded by an ancillaryinformation decoder 152, temporarily supplied to the control circuit132, and used to display its contents on a display of the control panel,to supply the information to the character generator 147 to display theinformation on a monitor screen, to supply data to an external personalcomputer, or to control the operation mode of the VTR.

Simultaneously with recording/reproducing operations for the video dataand audio data, a CUE audio signal, a time code signal representing timeinformation, and a control track signal serving as a reference fortracking are recorded/reproduced using the fixed head 111. The CUE audiosignal is set such that an externally input signal and a signal havingan arbitrary number of channels and selected from digital recordingaudio signals input to the input terminal 117 can be selectivelyrecorded. For this reason, during a variable-speed reproducing operation(a fast-forward operation, a rewinding operation, a slow reproducingoperation, or the like), a searching operation by an audio signal, and acue operation can be performed.

The above signal processing on a linear track is performed in aTC/CTL/CUE recording/reproducing circuit 153.

The rotation of the rotary drum 11, the rotation of the capstan 110, andthe rotation of the supply reel 18 for driving a cassette tape arecontrolled by a servo circuit 154.

Although a time code signal is recorded on a linear track as timeinformation required for editing or searching, when the VTR is stoppedor slowly operated, the time code signal cannot be read. Therefore, atime code is also recorded on a helical track, and the time code on thehelical track is used when the time code on the linear track cannot beread.

In a conventional VTR, since time code data has been additionallyrecorded in part of the audio or video sector for a recorded signal,only the time code data has not been able to be independently edited(after-recorded). On the other hand, since a VTR in which an HDTV("high-vision") signal of the 1125/60 scheme is digitally recorded has avery high data rate, i.e., 1.188 Gbps and requires many high-performanceaudio channels, a helical track has no margin for forming a time codearea which can be independently edited. In this VTR, a European 1250/50HDTV signal or a U.S. 1050/59.94 HDTV signal is to be recorded with asmall number of change portions. In this case, since the European schemeor the U.S. scheme has an image information data rate lower than that ofthe Japanese 1125/60 scheme, the above time code signal which can beindependently edited can be recorded in a redundant recording area, orother information signals can be recorded in the redundant recordingarea.

In the first embodiment, N tracks are defined as one segment, and adigital VTR capable of recording a signal in a first HDTV scheme inwhich video data to be recorded per segment has P bits and a signal in asecond HDTV scheme in which video data to be recorded per segment has Qbits (P>Q) is one for recording a plurality of HDTV signals, which ischaracterized in that time code data constituted to be able to beindependently erased and rewritten in at least one portion of onesegment is recorded when the signal is recorded in the second HDTVscheme.

In this case, the first HDTV scheme is the 1125/60 scheme, and thesecond HDTV scheme is the 1250/50 scheme.

In addition, the first HDTV scheme is the 1125/60 scheme, and the secondHDTV scheme is the 1050/59.94 scheme.

In the first embodiment, a tape is wound on a head drum through almost180°, and 16 recording heads are arranged on the head drum, therebyperforming a recording operation. The drum is rotated 150 times persecond, 8 tracks corresponding to 1/2 revolutions of the drum aredefined as one segment, and a 1125/60 "high-vision" signal is recordedfor 5 segments per field.

FIG. 2 is a schematic view showing a track arrangement on a tape. Eighttracks are defined as 1 segment. Reference numerals 21a to 21g denote 7video tracks, and reference numeral 22 denotes a video/audio track. Thistrack 22 has 8-channel audio sectors, and the sectors are partitioned byedit gaps and constituted to be independently edited.

(a) in FIG. 3 is a view showing a 1-frame HDTV signal to be recorded. Avideo signal is a component signal consisting of a luminance signal andtwo chrominance signals, the luminance signal is sampled at 74.25 MHz,and each chrominance signal is sampled at 37.125 MHz (quantizationaccuracy: 8 bits). The number of horizontal samples of the luminancesignal is 2,200, and the number of horizontal samples of eachchrominance signal is 1,100. The numbers in the brackets represent thenumbers of samples of the chrominance signals. In the verticaldirection, 1,125 lines are arranged. In this VTR, only effective pixels32 except for a blanking period 1 are recorded, 1,920 (960) samples arearranged in the horizontal direction, and 1,035 lines are arranged inthe vertical direction. A data area of 5 lines are additionally recordedas a data area which can be freely defined and used by a user. The1-frame recorded data is divided into field data 33a and 33b each having520 lines as shown in FIG. 3(b), and 1-field data is recorded within atime corresponding to 2.5 revolutions (5 segments) of the drum.

After these data are coded by the ECC encoder 122 in FIG. 1 to correctan error, the data are divided into 8-channel data, and the divided dataare channel-coded by the modulator 128. Sync information from the syncinformation generator 130 is added to the channel-coded data, and theresultant data are recorded on the tape through the recording amplifiers14 using the 16 recording heads 12. Assuming that 8 bits are defined asone symbol, as shown in FIG. 4, video data recorded on a video track 41has 60,720 symbols, and video data recorded on a video/audio track 42has 46,000 symbols. The recorded video data includes redundant bits ofan error correction code or an address. A preamble 43 and a post-amble44 are formed after and before each track, and audio sectors 45a to 45hof 8 channels are arranged to be interposed by edit gaps 46a and 46b orthe like. Each audio sector has a unique preamble 47 and a uniquepost-amble 48.

An embodiment in which signals of HDTV schemes proposed in Europe andthe United States are recorded in this VTR will be described below.

A 1250/50 scheme is proposed in Europe. That is, in this scheme, thenumber of lines per frame is 1,250, and a field frequency is 50 Hz. (a)in FIG. 5 shows a 1-frame video signal. In (a) in FIG. 5, the luminancesignal is sampled at 72 MHz, and the two chrominance signals are sampledat 36 MHz (quantization accuracy: 8 bits). The number of horizontalsamples of the luminance signal is 2,304, and the number of horizontalsamples of each chrominance signal is 1,152. The numbers in the bracketsrepresent the number of samples of the chrominance signals. In thevertical direction, 1,250 lines are arranged. In this VTR, onlyeffective pixels 52 except for a blanking period 51 are recorded, 1,920(960) samples are arranged in the horizontal direction, and 1,152 linesare arranged in the vertical direction. A data area of 48 lines isadditionally recorded as a data area which can be freely defined andused by a user. The 1-frame recorded data is divided into field data 53aand 53b each having 600 lines as shown in (a) in FIG. 5, and 1-fielddata is recorded within a time corresponding to 3 revolutions (6segments) of the drum. The number of all symbols which can be recordedper recording track is the same as that of the 1125/60 scheme. Dataarrangements on tracks in the 1250 scheme are shown in FIG. 6. Althoughthe 60,720 symbols are recorded on the video track of the 1125 scheme,the number of symbols recorded on a video track 1 is 60,384 in the 1250scheme. Although a difference of 336 symbols 62 between the symbols ofthe 1125 scheme and the symbols of the 1250 scheme is added to a margin63, the symbols 62 may be used for another application. On the otherhand, although video data to be recorded on a video/audio track has46,000 symbols in the 1125 scheme, video data to be recorded on avideo/audio track has 31,968 symbols in the 1250 scheme, and a blankspace 65 corresponding to 14,032 symbols is formed. Time code data 67between edit gaps 66a and 66b and user data 68 are newly formed in theblank space 65. Preambles 69a and 69b and post-ambles 610a and 610b areadded before and after the data 67 and 68, respectively. In a time codedata unit, time information having 32 bits per frame as in informationrecorded on a linear track and error-corrected and coded 32-bit timeinformation having the same code arrangement as in video data or audiodata are recorded a plurality of times. The user data is coded likevideo data and recorded a plurality of times like video data, therebyincreasing reliability of information. The identification information ofthe time code data and the user data are recorded in the preambles 69aand 69b and included in the code arrangements of these data,respectively.

In this embodiment, although the time code data and the user data arearranged as shown in FIG. 6, the time code data or the user data can beseparately arranged at several portions of the track within a limit ofthe total number of symbols of one track. In addition, the user data canbe omitted, and the number of channels for audio data can be increasedin place of the user data.

An embodiment in which a signal of a 1050/59.94 scheme proposed in theUnited States is recorded will be described below.

In this scheme, the number of lines per frame is 1,050, and a fieldfrequency is 59.94 Hz. This field frequency is different from a fieldfrequency of 60 Hz by 0.1%. For this reason, in a VTR, when the numberof revolutions of a drum, a tape speed, and a recording data rate aredecreased by 0.1%, the other can be handled as in the scheme having thefield frequency of 60 Hz. (a) in FIG. 7 shows a 1-frame video signal.Referring to (a) in FIG. 7, a luminance signal is sampled at a frequencyof 72 MHz, and two chrominance signals are sampled at a frequency of 36MHz (quantization accuracy: 8 bits). The number of horizontal samples ofthe luminance signal is 2,288, and the number of horizontal samples ofeach chrominance signal is 1,144. The numbers in the brackets representthe numbers of samples of the chrominance signals. The video signal has1,050 lines in the vertical direction. In this VTR, only effectivepixels 72 except for a blanking period are recorded, 1920 (960) samplesare arranged in the horizontal direction, and 966 lines are arranged inthe vertical direction. A data area of 34 lines is additionally recordedas a data area which can be freely defined and used by a user. As shownin (b) in FIG. 7, 1-frame recorded data is divided into field data 73aand 73b each having 500 lines, and 1-field data is recorded within atime corresponding to 2.5 revolutions of the drum (5 segments). Thetotal number of symbols which can be recorded per recording track isequal to that of the 1125/60 scheme. In the 1050 scheme, dataarrangements on tracks are shown in FIG. 8. Although the number ofsymbols recorded on a video track in the 1125 scheme is 60,720, thenumber of symbols recorded on a video track 81 is 58,608. Although thedifference between the number of symbols in the 1125 scheme and thenumber of symbols in the 1050 scheme, i.e., 2,112 symbols 82, is addedto a margin 83 of the track, and the symbols 82 can be used for anotherapplication. In particular, in the 1050 scheme, since the number ofexcessive symbols is large, time code data having an edit gap can alsobe recorded on the video track.

On the other hand, although video data to be recorded on a video/audiotrack of the 1125 scheme has 46,000 symbols, video data to be recordedon a video/audio track of the 1050 scheme has 31,968 symbols, and ablank space 85 corresponding to 14,032 symbols is formed. As in the 1250scheme, edit gaps 86a and 86b, time code data 87, and user data 88 areformed in this blank space 85. Preambles 89a and 89b and post-ambles810a and 810b are added before and after the time code data 87 and theuser data 88, respectively. In this 1050 scheme, the same time code dataand user data as those used in the 1250 scheme can be used.

In this embodiment, although the time code data and the user data arearranged as shown in FIG. 6 or 8, recorded data on the video track maybe reduced to form a space, and time code data may be recorded at oneportion or several portions. In short, a time code recording area can befreely set within a range of an excessive data area in one segment.

In the above first embodiment, 8 tracks are used as a unit. Although anAUDIO signal is concentrated and recorded on one specific track in onesegment, another method of recording the AUDIO signal can be used. Thesecond embodiment in which this method is used as an example will bedescribed below.

In this embodiment, an audio signal is recorded as shown in FIG. 9. FIG.9 shows a 1-field track pattern of a 1125/60 scheme. Reference numeral901 denotes a video recording area, and reference numeral 902 denotes anaudio recording area. That is, audio recording areas are formed in alltracks, the 1-field audio signal of the same channel is recorded onadjacent tracks (4 tracks). In the 1125/60 scheme or the 1050/59.94scheme, an audio signal of 10 channels (8 channels+2 optional channels)can be recorded. In the 1250/50 scheme, an audio signal of 12 channels(8 channels+4 optional channels) can be recorded.

In an editing operation, due to a tracking error in the direction of thetrack width, tracks are not completely erased, or non-edited tracks areerased. An error rate easily increases in the tracks immediately beforeand after an edition point. For this reason, when an editing operationis performed in units of fields, a track adjacent to an end portion of afield, i.e., an edition point, is damaged easier than other tracks.Therefore, according to this embodiment, as shown in FIG. 9, the twoaudio channels arranged at the end portions of the field are assigned asoptional channels OP1 and OP2. In each optional channel, data having thesame contents as those of an arbitrary audio channel may be recorded asbackup data.

FIG. 10 is an enlarged view showing an audio recording area of onechannel, i.e., four tracks, in FIG. 9. The audio data are written in theaudio recording area twice. Data E or O is recorded twice such that thedata E related to even-numbered samples is recorded on tracks 903 and905 and the data O related to odd-numbered samples is recorded on tracks904 and 906.

In this recording scheme, audio pre-reproducing heads (used in an audioediting operation) of the same number as the number of reproducing headsare required. However, since the same data is written twice, when onlyone of the data is reproduced only in a pre-reproducing operation, thenumber of pre-reproducing heads can be set to be 1/2 the number ofreproducing heads.

At this time, it will be described which one of the two writtenidentical data is reproduced by the pre-reproducing heads. In therecording scheme shown in FIGS. 9 and 10, when an insert editingoperation is performed in units of audio channels, the 4 adjacent audiorecording areas of the same channel are necessarily rewritten at once.More specifically, since, of the 4 tracks, two tracks (indicated by 903and 906 in FIG. 10) at the end portions are adjacent to the editionpoints, the two tracks are easily damaged by an editing operation due tothe above reason. The two inner tracks (indicated by 904 and 905) arenot easily damaged. For this reason, since each of the two tracksadjacent to the edition points and located at the end portions probablyhas a high error rate, the two tracks at the end portions are not to besubject to the pre-reproducing operation. Therefore, the pre-reproducingheads are preferably arranged to scan the two inner tracks.

As described above, even when an audio recording area is formed on eachof all tracks as shown in FIG. 9, only one of the two written identicaldata is pre-reproduced. At this time, when tracks adjacent to editionpoints are not included in tracks to be pre-reproduced, the number ofaudio pre-reproducing heads can be reduced to 1/2 the number ofreproducing heads, and the number of errors of data to be pre-reproducedcan be minimized.

As an audio signal recording scheme, schemes shown in FIGS. 11 to 14 canbe considered. Each of FIGS. 11 to 14 shows 40 tracks corresponding toone field used when an audio signal of 10 channels is recorded in the1125/60 scheme. Reference numerals in FIGS. 11 to 14 denote audiochannel numbers, respectively. (1-a) to (1-d) in FIG. 11 show a schemeof recording an audio signal of the same channel on 8 tracks using 8tracks as one unit, (2-a) and (2-b) in FIG. 12 and (3-a) to (3-d) inFIG. 13 show a scheme of using 4 tracks as one unit, and (4-a) and (4-b)in FIG. 14 show a scheme of forming an audio recording area on apredetermined number of tracks of 8 tracks. The example shown in FIG. 9corresponds to the example shown in (2-a) in FIG. 12.

An embodiment in which tapes recorded in different schemes arereproduced will be described below.

In a digital VTR coping with a plurality of schemes (the 1125/60 scheme,the 1050/59.94 scheme, and the 1250/50 scheme) having the differentnumbers of scanning lines and different field frequencies, the pluralitytypes of schemes are set by switching a switch or the like. When ascheme set by this switch, the scheme of an input reference signal, anda scheme identified by a tape are different from each other, video datacannot be reproduced by a conventional VTR. More specifically, whencontents are recorded in a given scheme (first scheme) on a tape, videodata corresponding to the contents cannot be reproduced and displayed ona monitor in the second scheme.

According to the third embodiment, the contents of video data recordedin different schemes can be confirmed, and video data recorded indifferent schemes can be reproduced by performing scheme conversion.

More specifically, according to the third embodiment, a digital VTR hasmodes for reproducing signals recorded in a plurality of schemes havinga difference in at least one of the number of scanning lines and thefield frequency, and this digital VTR has the following characteristicfeature. That is, the digital VTR comprises a memory in a reproducingcircuit and has a mode for writing data in the memory in a methodcorresponding to the first scheme and reading the data from the memoryin a method corresponding to the second scheme.

The third embodiment of the present invention will be described below.

According to this embodiment, a digital VTR for separately recordingdata in 8 channels is considered. The number of tracks per field isdetermined to be 40 in the 1125/60 scheme or the 1050/59.94 scheme, andthe number of tracks per field is determined to be 48 in the 1250/50scheme. That is, the number of tracks of one channel per field is 5 inthe 1125/60 scheme or the 1050/59.94 scheme, and the number of tracks ofone channel per field is 6 in the 1250/50 scheme. The arrangement of anerror correction code is completed within 5 tracks (or 6 tracks).

One-field data to be actually recorded in this embodiment is shown inFIG. 15. The number of recording lines per field is 520 in the 1125/60scheme or the 1050/59.94 scheme as shown in (a) in FIG. 15, and thenumber of recording lines per field is set to be 624 in the 1250/50scheme as shown in (b) in FIG. 15. The number of samples per line doesnot depend on the schemes. That is, the number of samples of a luminancesignal is 1,920, and the number of samples of a chrominance signal is960.

The data is divided into 8-channels data. With respect to data of eachchannel, an error correction matrix shown in FIG. 16 is constituted.That is, C2 parity symbols of P2 symbols are added to symbolsrepresenting the number (120) of C2 information symbols, and C1 paritysymbols of P1 symbols are added to symbols representing the number (104)of C1 information symbols. (e.g., P1=P2=8 is set). FIG. 17 shows thearrangements of 1-field, 1-channel data. Twenty error correctionmatrices 0 to 19 shown in FIG. 16 are arranged in the 1125/60 scheme orthe 1050/59.94 scheme as shown in (a) in FIG. 17, and 24 errorcorrection matrices 0 to 23 are arranged in the 1250/50 as shown in (b)in FIG. 17. (Note that a C1 parity symbol is omitted in FIG. 4). Theseerror correction matrices are divided into five portions (or 6 portions)in the column direction as shown in the right side of (a) or (b) in FIG.17. The error correction matrices are divided into five tracks 0 to 4and recorded in the 1125/60 scheme or the 1050/59.94, and the errorcorrection matrices are divided into six tracks 0 to 5 and recorded inthe 1250/50 scheme. As a result, an amount of data per track does notdepend on the schemes, and the same amount of data per track can beobtained in each of the different schemes.

A recording operation is performed in units of sync blocks. An ID(identification) code representing a field number, a channel number, atrack number, and a sync block number in a track is added to each syncblock.

FIG. 18 shows schematic views showing address assignment performed whendata is actually stored in a field memory. Addresses are basicallyassigned in an address recording order, i.e., a sync block ID order.Addresses of 5 tracks are assigned in the 1125/60 scheme or 1050/50.94scheme as shown in (a) in FIG. 18, and addresses of 6 tracks areassigned in the 1250/50 scheme as shown in (b) in FIG. 18.

A rule (shuffling) used when data on the screens shown in FIG. 15 arearranged as shown in FIG. 17 in one of the two schemes, i.e., the1125/60 scheme and the 1050/60 scheme is different from that in the1250/50 scheme due to the difference in number of recording lines and adifference in numbers of error correction matrices. In addition, therelationship between the data arrangement shown in FIG. 17 and therecording order shown in FIG. 18 and determined by the sync block ID inone of the 1125/60 scheme and the 1050/59.94 scheme is different fromthe relationship between the data arrangement shown in FIG. 17 and therecording order shown in FIG. 18 and determined by the sync block ID dueto the difference between the numbers of error correction matrices andthe difference between the numbers of recording tracks.

FIG. 19 is a view showing the arrangement of an error correction circuit136 (and a circuit related to the error correction circuit 136) in thereproducing circuit of the digital VTR in FIG. 1 according to thisembodiment. Referring to FIG. 19, a reproduced signal input to the errorcorrection circuit is subjected to decoding of a CI code in a CIdecoding circuit 1901, and is written in one field memory or a pluralityof field memories of four reproducing field memories 1902a to 1902d. Inthis writing operation, a write address (real address of field memory)is synthesized in a write address generation circuit 1905 on the basisof an ID detected by an ID detection circuit 1904. The roles of thereproducing field memories 1902a to 1902d are deshuffling (reverseconversion of shuffling) and storing of data in a variable-speedreproducing operation. Data read from any one of the reproducing fieldmemories is subjected to decoding of a C2 code in a C2 decoding circuit1903, and is output from the error correction circuit. At this time, aread (deshuffling) address is generated by a read address generationcircuit 1906. As described above, a method of generating a read addresschanges depending on the schemes.

A control operation is performed by a control circuit 1907, and thecontrol circuit 1907 generates a channel system (write system) controlsignal 1924 and a video system (read system) control signal 1925. Anoutput (video system) reference signal 1922 is supplied to a timingsignal generation circuit 1909, thereby generating a timing signal. Atthe same time, a scheme identification result from the output referencesignal 1922 is supplied to a mode setting circuit 1908, and a servoreference signal 1923 is generated. In this case, different basic clockfrequencies are used in the channel system and the video system,respectively. Although the same clock of the channel system is usedregardless of the schemes, the clock of the video system changesdepending on the schemes due to the difference in video samplingfrequency.

The scheme of data recorded on a tape is identified by a cassette mainbody or contents recorded on the longitudinal or helical tracks of thetape, and a scheme identification signal 1921 corresponding to thecontents of the tape is supplied to the mode setting circuit 1908. Inthe mode setting circuit 1908, an operation mode of the VTR isdetermined with reference to the scheme identification result of thescheme identification signal 1921 or the output reference signal 1922 ora setting performed by a switch (not shown). When the setting by theswitch conflicts with the reference signal or the scheme identificationsignal, a correct reproducing operation cannot be performed. For thisreason, video data is inhibited from being output. However, in adifferent scheme reproducing mode, even when the scheme of the contentsof a tape is different from the scheme of an output reference signal,the control circuit 1907 is operated to perform recording/reproducingoperations. More specifically, if the scheme of the contents of the tapeis the first scheme, the channel system control signal 1924corresponding to the first scheme is generated. If the scheme of theoutput signal 1922 is the second scheme, a video reference signal 125corresponding to the second scheme is generated. At this time, the servoreference signal 1923 corresponding to the first scheme is generated bya timing signal generation circuit 109.

An operation performed when a tape recorded in a single scheme isnormally reproduced by a VTR will be described below. In this case, anexample wherein a tape recorded in the 1125/60 scheme is reproduced willbe described below. The output reference signal 1922 having a frequencyof 30 Hz and using the 1125/60 scheme is externally supplied to thetiming signal generation circuit 1909, thereby generating the servoreference signal 1923 having a frequency of 30 Hz. The control circuit1907 generates the channel system control signal 1924 and the videosystem control signal 1925 corresponding to the 1125/60 scheme.

FIG. 20 shows a control operation of the four reproducing field memories1902a to 1902d (#1 to #4) in a normal reproducing operation. Referringto FIG. 20, the phase of a reproducing reference signal (servo referencesignal) and the phase of an output reference signal are locked with eachother. At this time, reproduced data are supplied to reproducing fieldmemories at timings shown in FIG. 20. Referring to FIG. 20, "0" denotesreproduced data of an even-numbered field, and "1" denotes reproduceddata of an odd-numbered field. Suffixes 0 and 1 represent aneven-numbered field and an odd-numbered field, respectively. Forexample, reference symbol WO represents that data are written in thefield memories of only an even-numbered field.

As shown in FIG. 20, a switching operation between write access and readaccess is performed in units of fields, and data are sequentially readfrom the four field memories #1 to #4 using four fields as a period.Write access is performed in two fields before read access. In writeaccess, a write address corresponding to the 1125/60 scheme is generatedon the basis of an ID. In addition, a read address corresponding to adeshuffling method of the 1125/60 scheme is generated. As describedabove, write access and read access to the reproducing field memoriesare generally performed in accordance with the same scheme.

A case wherein tapes of different schemes are reproduced. In thisembodiment, a control scheme is changed into another before and after areproducing field memory. In this case, the 1125/60 scheme and the1250/50 scheme will be described.

Assuming that the 1250/50 scheme is used as the first scheme, it isconsidered that a tape recorded in the first scheme is reproduced inaccordance with the 1125/60 scheme (second scheme). Although a 30-Hzoutput reference signal 122 of the 1125/60 scheme is externally suppliedto the timing signal generation circuit 109, a 25-Hz servo referencesignal is generated. This 25-Hz reference signal may be generated inasynchronism with the external 30-Hz reference signal. (Depending on acase, a servo reference signal may not be supplied in units of frames,i.e., framing control may not be performed.) In addition, if a processperformed before write access to the reproducing field memory isperformed partially changes depending on schemes, a channel systemcontrol signal 124 is generated in accordance with the 1250/50 scheme.More specifically, if a process for the length of a sync block or a syncpattern, a modulation method, and a process for an ID change dependingon schemes, these processes depend on the 1250/50 scheme. A writeaddress is generated in accordance with the 1250/50 scheme. However, inthe format of this embodiment, these processes are performed almostindependently of the schemes.

A control operation of the reproducing field memories 102a to 102dperformed in the above case is shown in FIG. 21. A switching operationbetween write access and read access is performed in units of fields ofthe 1125/60 scheme. As in the case shown in FIG. 20, a read field memoryis switched in a 4-field period. However, as is apparent from FIG. 21,the field of reproduced data is gradually deviated from the outputreference signal along the time axis. Therefore, write access is alwaysperformed except for a time when read access is performed, a field ID isnot discriminated in write access, and both reproduced data of even- andodd-numbered fields are written. The video system control signal 1925 isgenerated such that a process after read access to the field memories isperformed in accordance with the second scheme, i.e., the 1125/60scheme.

The above control operation can be considered to be almost the same as acontrol operation performed during a shuttle reproducing operation(high-speed reproducing operation) in a digital VTR. In this case,however, since a plurality of fields are mixed with each other anddisplayed, image quality (resolution) is degraded. Note that a switchingoperation between write access and read access to the reproducing fieldmemories may be performed by a method of performing a time-divisionaloperation in units of clocks in place of units of a time-divisionalmethod using fields.

Another control operation of the reproducing field memories 1902a to1902d is shown in FIG. 22. In this operation, the same field isrepetitively reproduced. It is determined by the value of a field IDdetected in the ID detection circuit 104 whether an input operation of afield is completed, and a reproducing field memory to which read accessis performed is determined in the next field. For example, in a fieldnext to a point A in FIG. 22, although read access is to be performed toa field memory #3, since an input operation of reproduced data of thefield memory #3 is not completed, read access to the field memory #3 isnot performed, and read access to the field memory #2 is performedagain. Similarly, in the field next to a point B, although read accessis to be performed to a field memory #4, since an input operation ofreproduced data of the field memory $4 is not completed, read access isnot performed to the field memory #4, and read access to the fieldmemory #3 is performed. That is, read access to the same field isrepeated once for six fields.

In this case, when the parity of the field of an output reference signaldoes not coincide with that of a read field, a height error in avertical direction is preferably corrected. Since the parity of the readfield is inverted in the interval between the point A and the point B inFIG. 22, a field correction signal goes to high level, and the heighterror of the field in the vertical direction is performed. The abovecontrol operation may be considered to be almost the same as anoperation performed during a slow-motion reproducing operation in adigital VTR.

Assuming that the 1125/60 scheme is used as the first scheme, it isconsidered that a tape recorded in the first scheme is reproduced inaccordance with the 1250/50 scheme (second scheme). A control signal andthe like are inverted to those of the above operation. In this case, incontrast to the case shown in FIG. 22, an example wherein fields areinterleaved will be described. A control operation of the reproducingfield memories 1902a to 1902d performed at this time is shown in FIG.23. It is determined by the value of a field ID detected by the IDdetection circuit 1904 whether an input operation of a field iscompleted, and a reproducing field memory to which read access isperformed is determined in the next field. For example, in the fieldnext to a point C in FIG. 23, although read access is to be performed toa field memory #4, since an input operation of reproduced data of afield memory #1 next to the field memory #4 is completed, read access isnot performed to the field memory #4, but read access to the fieldmemory #1 is performed. Similarly, in the field next to a point D,although read access is to be performed to a field memory #2, since aninput operation of reproduced data of a field memory #3 next to thefield memory #2 is completed, read access is not performed to the fieldmemory #2, and read access is performed to the field memory #3. That is,interleaving for field read access is performed once for five fields.

Since the parity of a read field is inverted in the interval between thepoint C and the point D in FIG. 23, a field correction signal goes to Hlevel, and the height error of the fields in the vertical direction isperformed. Note that, when a reproducing operation is performed byconverting the 1125/60 scheme into the 1250/50 scheme, as in the case inFIG. 21, a control operation according to a shuttle reproducingoperation may be performed.

Although the reference signals of the two schemes are asynchronized witheach other or have indefinite phases in each of the examples describedabove, the reference signals may be synchronized with each other using aPLL circuit or the like. When the reference signals are synchronizedwith each other, interleaving for regular fields can be easily repeatedwithout a circuit for determining whether an input operation of areproducing field is completed.

In the above embodiments in FIGS. 22 and 23, simple scheme conversionsuch as field interleaving or field repetition is described. However,when more advanced scheme conversion such as field interpolation isperformed, artificial motions can be eliminated, and the quality of areproduced image is improved as a matter of course. That is, aninterpolated signal is obtained by calculation (linear interpolation orthe like) of data read from two or more field memories. In this case,however, the number of field memories must be generally increased.

A control operation performed when read access is performed to areproducing field memory in accordance with the second scheme will bedescribed below in detail. In addition, since the number of effectivesamples in the lateral direction is constant independently of schemes,read access within one line can be performed without causing anyproblem. However, as described above, a plurality of schemes have thedifferent numbers of effective lines, respectively. Therefore, when asignal of the first scheme is displayed on a monitor using the secondscheme, the lower portion of a screen is cut when the number of lines ofthe second scheme is smaller than the number of lines of the firstscheme, and indistinct noise data may be displayed on the lower portionof the screen when the number of lines of the second scheme is largerthan the number of lines of the first scheme.

For this reason, when the number of lines of a monitor (second scheme)is large, a start line of read access to a reproducing field memory isoffset (i.e., a start of read access to effective lines is delayed) suchthat an area in which an image is displayed is located at the almostcentral portion of the screen, and the upper and lower portions of thescreen are converted into portions represented by black level or graylevel to prevent indistinct noise data from being displayed, so thatso-called letter box display may be performed. In contrast to this, whenthe number of lines of the monitor (second scheme) is small, a startline of read access may be offset such that the upper and lower portionsare uniformly cut (i.e., the start of read access to effective lines isadvanced).

At this time, however, the screen on the monitor may display a picturewhich is entirely compressed or expanded in all directions. In order toprevent a picture from being compressed or expanded due to theexcessiveness or shortage of the number of lines, read access to thesame line may be repeated, or interleaving of read lines may beperformed. In addition, line interpolation (e.g., linear interpolation)may be performed using data of two or more lines.

In the above description, although the 1125/69 scheme and the 1250/50scheme are used as the first and second schemes, respectively, even whenthe 1050/59.94 scheme or other schemes are used as the first and secondschemes, the same effect as described above can be obtained. However,conversion between the 1125/60 scheme and the 1050/59.94 scheme can berealized easier than the conversion described above, if the difference(0.1%) between the display speeds of these schemes is allowed.

As described above, when a control operation similar to a shuttlereproducing operation or a slow reproducing operation is performed, thecontents of tapes recorded in different schemes can be satisfactorilyconfirmed without adding any hardware. In addition, in order to obtainsatisfactory quality of an image of a tape by a VTR using a schemedifferent from that of the tape, reference signals are synchronized witheach other, and professional scheme conversion may be performed byperforming field interpolation or line interpolation.

The present invention is not limited to the above embodiment, and thepresent invention can be used in various applications. For example, byusing a shuffling field memory on a recording side, a recordingoperation may be performed while scheme conversion is performed duringthe recording operation.

In the above embodiment, the number of lines per field and the number ofC1 information symbols per field are set to be 520 and 104 in the1125/60 scheme, respectively; 500 and 100 in the 1050/59.94 scheme,respectively; and 600 and 100 in the 1250/50 scheme, respectively. Inaccordance with this, a sync block length or a recording wavelength maybe changed depending on the systems.

A method of identifying different schemes in use of the same cassettewill be described below.

This embodiment in which a bar-code label obtained by describingrepresenting identification information for identifying a plurality ofpieces of scanning line information on a cassette case, a magnetic card,a memory card, a selection switch are attached, comprises a pickup meansfor obtaining scanning line identification information when a cassetteis inserted or set or when a tape runs from the start position, afunction of switching a recording/reproducing signal processing circuitin accordance with the obtained scanning line identification informationto display scanning line information, a means for storing the obtainedscanning line identification information, and a means for supplying andfor rewriting the stored identification information to the scanning lineinformation identification storage means when the cassette is ejected.

In this manner, since the identification information storage means for aplurality of scanning line schemes is arranged on the cassette case or amagnetic tape, a recording/reproducing operation can be automaticallyperformed in a desired scanning line scheme by identifying and storingthis information. In addition, since the identification information fora scanning line scheme is stored, the identification information for thescanning line scheme can be displayed by the pickup and displayfunctions at any time, and the identification information stored whenthe cassette is ejected is supplied to the identification informationstorage means for the scanning line scheme and the display means on thecassette case for displaying the above information and rewritten. Forthis reason, the identification information for the scanning line schemeon the cassette case can have redundancy.

The fourth embodiment will be described below with reference to theaccompanying drawings.

When scanning line schemes are different from each other in FIG. 15,recording system signal processing units 121, 122, and 127, reproducingsystem signal processing units 136, 140, and 152, and a circuit (timingpulse generator 126) for generating a control timing of a cassettedigital VTR with a reference signal are switched to a circuit operationcorresponding to each scanning line scheme using a control signal from acontrol circuit 132 by a method of identifying a scanning line scheme(to be described below).

FIG. 24 is a block diagram showing a portion related to identificationof scanning line schemes in FIG. 1. An embodiment of a method ofidentifying a scanning line scheme and an embodiment of a method ofdisplaying the scanning line scheme will be sequentially describedbelow. An embodiment of a method of identifying a scanning line schemeusing a bar-code label is described first. FIG. 25 is a view showing anembodiment wherein, when a cassette 16 to which a bar-code label 2501adheres is inserted into a cassette insertion port 155 in FIG. 1,scanning line identification information obtained by printing anddescribing a scanning line scheme on a bar-code label 2501 in advance isread by a laser detector 2502 arranged on a bucket 2503. Referring toFIG. 25, when the cassette is inserted, a detection circuit 2504 isactivated to read bar-code information by a control signal from thecontrol circuit 132 only when the cassette 16 is inserted. Theidentification information detected by the detection circuit 2504 issupplied to the control circuit 132, and becomes a circuit switchingsignal corresponding to the circuit operation of each scanning linescheme of a recording signal processing circuit 2400, a reproducingsignal processing circuit 2401, the timing pulse generation circuit 126,and a scanning line display circuit 2405. Since this identificationinformation is stored until the cassette is ejected or the cassette isreplaced with another, each scanning line scheme is confirmed by adisplay function (to be described later) at any time. As theidentification information, a simple 2-bit bar-code may be used becauseonly three types of scanning line schemes, i.e., the Japanese 1125/60scheme, the U.S. 1050/59.94 scheme, and the European 1250/50 scheme needbe identified. In addition, since the bar-code of the bar-code label2501 is hard to be read by the human eye, character information whichcan be immediately understood by man is printed on the bar-code label2501, and positions at which the bar-code label 2501 and the laserdetector 2502 on the cassette 16 are arranged are not restricted as amatter of course. In this manner, as an embodiment of another means foridentifying a scanning line scheme when a cassette is inserted, a methodusing a magnetic card 2600 in place of the bar-code label 2501 is shownin FIG. 26, and a method using an optical card 2700 is shown in FIG. 27.In the two cases, since identification information is stored bydifferent means, only the detector and detection circuit as hardwarecircuits are different from those of the embodiment using the bar-codelabel 2501 in FIG. 25. For this reason, a detailed description of thetwo cases will be omitted.

In each of the embodiments described above, identification is performedwhen a cassette is inserted. However, a method of an embodiment (to bedescribed next) is a method of identifying a scanning line scheme aftera cassette is set. FIG. 28 shows an embodiment using a memory card 600as a storage means of identification information. When insertion of thecassette 16 is completed, and the cassette 16 is set in a cassetteframe, the tangent portion of the memory card 2800 arranged on thebottom surface of the cassette 16 is brought into contact with a memorycard contact 2801 arranged on the cassette frame, and a memory controlcircuit 2802 is started by a control signal from the control circuit132, so that scanning line identification information is received by acontrol circuit 132 by a memory handshake signal. As a memory chipmounted in the memory card, a PROM, an EEPROM, or a CMOS ROM having abackup function may be used. Since processes performed after scanningline identification information is received by the control circuit 132are the same as those of the above description, a description thereofwill be omitted.

An identification method (to be described below) different from theabove electrical identification method is an embodiment using amechanical identification means as another means for identifying ascanning line scheme after a cassette is set. FIG. 29 is a view showingan embodiment wherein a scanning line scheme is identified by a rotaryselection switch 2900 arranged on the cassette 16 or a slide typeselection switch 2901 constituted by a slide plate 2903. Although aswitch position is identified by a detection device 2904, as shown inFIG. 30, a means which uses a method using a conductive plate 302 shownin (a) in FIG. 30 by the rotary structure of the bottom surface portionof the rotation-type selection switch 2900 to detect whether a contactpoint 303 of a pickup is in contact with a conductive portion (hatchedportion) of the conductive plate 302, a means for performing detectionusing a reflecting plate 304 and a photosensor 305 which are shown in(b) in FIG. 30, and a means for detecting the depth of a groove by aposition sensor 307 using a cam 306 shown in (c) in FIG. 30 to identifya scanning line scheme are used. In each of the above three methods,identification information is extracted by a mechanical detection meansand converted into an electrical signal, and scanning lineidentification information is received by the control circuit 132through the detection device 2904. Since processes performed after theidentification information is received are the same as those of theabove description, a description thereof will be omitted. Since theslide type selection switch 2901 is obtained by only replacing a rotaryplate 301 shown in FIG. 30 with a slide plate, a description thereofwill be omitted. Note that the selection switches 2900 and 2901 can alsobe switched in accordance with an externally supplied control signal.

In each of the embodiments described above, a method of permanentlyidentifying one of three types of scanning line schemes has beendescribed. However, there is the second method which does notpermanently identify one of three types of scanning line schemes. Thismethod can be achieved by switching the scanning line scheme of arecording/reproducing operation at an arbitrary position of a cassettetape or by adding the fourth free scanning line scheme information toscanning line identification information by a method of performing arecording/reproducing operation in an arbitrary scanning line scheme.Designation of a scanning line scheme performed when the free scanningline scheme is selected is switchably changed to a circuit operationcorresponding to the scanning line scheme of a recording/reproducingoperation by a switch on the operator control panel 131 in FIG. 1 or aswitch (not shown) arranged in the cassette VTR. In addition, whensetting of the cassette is completed, before a recording/reproducingoperation is started, a scanning line scheme can be switchably changedto another corresponding to the received scanning line identificationinformation as a matter of course.

An embodiment of a function of displaying a specific scanning linescheme in which a cassette set in a VTR perform s arecording/reproducing operation will be described below. A first meansserving as a scanning line display device 2405 for causing an operatorto recognize scanning line scheme information stored in a scanning linestorage circuit 2404 in FIG. 24 displays the scanning line schemeinformation on a display, an indicator, or a Pix Monitor 151 on anoperator control panel 131 (in FIG. 1) as character information or lampON information which can be immediately recognized with the human eye.An embodiment shown in FIG. 31 as the second means is an embodimentwherein a liquid crystal display (LCD display) 3100 is arranged on acassette case 16 to arrange a display means on the cassette itself,thereby performing a display operation. As a power supply for a drivecircuit 3102 of the liquid crystal display 3100, a very small battery ora solar battery may be used. In addition, the embodiment shown in FIG.32 is an embodiment wherein an audio signal output from a loudspeaker3201 by an audio signal generation circuit 3200 as the third meanscauses an operator to recognize a scanning line scheme. For example,when as a generated audio language, Japanese, American, and German orFrench are used in the Japanese 1125/60 scheme, the U.S. 1050/59.94scheme, and the Europe 1250/50 scheme, respectively, a scanning linescheme can be clearly discriminated from the remaining scanning lineschemes. Note that an audio switching operation between the audiolanguages may be automatically performed between the schemes, or theaudio language may be designated by a user. In any scheme, designationcan be performed such that an audio signal is output in a language whichis designated in advance, or a translated sentence can be displayed on ascreen as a superimposition without converting the language.

Although the embodiments described above are related to display of ascanning line scheme, an embodiment (to be described next) is related toa function of rewriting scanning line identification informationattached to a cassette case. When a scanning line scheme is switchablyselected by the above second method using a switch on the operatorcontrol panel 131 in FIG. 1 or a switch arranged in a cassette VTR, andthe cassette is ejected, scanning line identification information isrewritten in the magnetic card in FIG. 26, the optical card in FIG. 27,and the memory card in FIG. 28, when the cassette is ejected. When theselection switch shown in FIG. 29 is used, a scanning lineidentification information position is changed by the rotary mechanismshown in FIG. 30. The liquid crystal display (LCD display) in FIG. 31 isalso rewritten as a matter of course. However, since the scanning lineidentification information of the bar-code label in FIG. 25 cannot beautomatically rewritten, a message for replacing the bar-code label witha new one is displayed on the display on the control panel 131 or thePix Monitor 151 shown in FIG. 1, the scanning line identificationinformation is manually rewritten. In addition, since a magnetic card,an optical card, or memory card has a large memory capacity, not onlyscanning line identification information but also ancillary informationsuch as a recording date or a title can be stored in the magnetic card,optical card, or memory card.

An embodiment wherein identification information is recorded on a tapeand read during a tape reproducing operation at variable speeds will bedescribed below.

As one method, the following method can be considered. That is, a schemeidentification code is recorded in a sub-code area of a helical track asin a VTR, and the code is read during a reproducing operation todetermine a recording mode. However, although the recording mode can becorrectly determined at a normal reproducing speed, the identificationcode recorded on the helical track cannot be necessarily and correctlyread during a slow reproducing operation or a high-speed reproducingoperation (shuttle reproducing operation) which is an indispensable modein a VTR because the recording heads diagonally cross the recordingtracks.

Information for determining a recorded signal is important informationhaving the highest rank in the operation modes of the VTR, and therecorded signal must be always correctly determined because of thefollowing reason. If the determination is erroneously performed, notonly quality of reproduced video data is degraded, but also the videodata fails to be strongly damaged. Depending on a case, amechanism/control system fails to damage the VTR main body and thecassette tape, and expensive HDTV software may be broken.

This embodiment has an object to stably, correctly determine a recordingmode in the above special reproducing operations and to provide stablereproduced video data in any operation mode.

The first embodiment is an embodiment for recording/reproducing scanningline identification information on a cue track of longitudinal tracks ona magnetic tape shown in FIG. 2. In an industrial VTR, the test signalsfor video data and audio data and a title are necessarily recorded atthe start position of a tape. An identification signal is recorded on acue track of this position, and a recording/reproducing operation isperformed. FIG. 33 is a view showing this embodiment. In a recordingoperation, as shown in FIG. 34, three types of signals respectivelyhaving frequencies of, e.g., 1 kHz ((a) in FIG. 34), 5 kHz ((b) in FIG.34), and 10 kHz ((c) in FIG. 34) are output from an oscillation circuit3300. One of these signals is selected by a selection circuit 3301 usinga control signal output from a control circuit 32 only when a recordingoperation of the start position of the tape is performed, and scanningline identification information is recorded on the cue track. In areproducing operation, on the basis of the scanning line identificationinformation recorded on the cue track, a scanning line identificationsignal is obtained by a signal identification circuit 1202 using acontrol signal output from the control circuit 32 only when datarecorded at the start position of the tape is reproduced. In thisembodiment, although sine waves respectively having frequencies of 1kHz, 5 kHz, and 10 kHz are used as the scanning line identificationinformation, any combination of waves having waveforms which can bediscriminated from each other may be used.

In this manner, according to the present invention, scanning lineidentification information recorded on a cassette case or scanning lineidentification information on a cue track is read so that a circuitoperation corresponding to the read scanning line identificationinformation can be automatically performed.

In the next embodiment, an identification signal is recorded on acontrol track in FIG. 2.

More specifically, an identification signal representing the type of theinput video signal is superposed on a control track signal having theframe frequency of a video signal or a frequency as an integer multipleof the frame frequency and recorded on a longitudinal track in a taperunning direction.

At this time, the frame frequency signal and the identification signalrepresenting the type of the input video signal are alternatelymultiplexed. The ratio of a frame frequency to the identification signalfrequency is represented by an integer. In addition, the frequency ofthe identification signal to be multiplexed is set to be the greatestcommon measure 1/N (N: integer) of different frame frequenciescorresponding to different video signals.

As another method, the number of pulses of an identification signal tobe multiplexed is changed in accordance with different video signals,and the identification signal is recorded.

In this embodiment, in order to identify three types of video signalsrespectively having frame frequencies of 30 Hz, 25 Hz, and 59.94/2 Hz,identification signals having different frequencies in correspondencewith the video signals are intermittently multiplexed with a controltrack signal which is conventionally recorded in a longitudinal tapedirection. FIG. 35 is a block diagram showing a TC/CTL/CUErecording/reproducing circuit 153 according to this embodiment. Theoscillation frequency of an oscillation circuit 1 (15301) is 600 Hz, andan output a1 from the oscillation circuit 1 is input to a frequencydivision circuit 1 (15302) and a frequency division circuit 2 (15304).The frequency division circuit 1 outputs a 120-Hz pulse signal b1obtained by frequency-dividing the oscillation circuit output a1 by 5, a60-Hz pulse signal b2 obtained by frequency-diving the signal b1 by 2,and a pulse signal b3 obtained by frequency-dividing the signal b2 by 2.The 120-Hz pulse signal b1 and the 60-Hz pulse signal are switched bythe first 30-Hz frame pulse signal b3 in a switching circuit 1 (15303)to generate a control signal c1 corresponding to the first video signal.The frequency division circuit 2 (15304) outputs a 200-Hz pulse signalb4 obtained by frequency-dividing the oscillation circuit output a1 by3, a 50-Hz pulse signal b5 obtained by frequency-dividing the pulsesignal b4 by 4, and a 25-Hz pulse signal b6 obtained by frequency-divingthe pulse signal b5 by 4. A switching circuit 2 (15305) switches the200-Hz pulse signal b4 and the 50-Hz pulse signal b5 by the second framepulse signal b6 to output a control signal c2 corresponding to thesecond video signal. The oscillation frequency of an oscillation circuit2 (15306) is 6⁻⁻ 59.95 Hz, and an output signal a2 from the oscillationcircuit 2 is input to a frequency division circuit 3 (15307). Thefrequency division circuit 3 (15307) outputs a pulse signal b7 having afrequency of about 180 Hz obtained by frequency-dividing the oscillationcircuit output a2 by 2, a 59.95-Hz pulse signal b8 obtained byfrequency-dividing the pulse signal b7 by 3, and a pulse signal b9obtained by frequency-dividing the pulse signal b8 by 2. The pulsesignal b7 having a frequency of about 180 Hz and the 59.94-Hz pulsesignal are switched by the third 59.94/2-Hz frame pulse signal b9 in aswitching circuit 3 (15308) to generate a control signal c3corresponding to the third video signal. A selection circuit (15309)selects one of the three types of control signals c1, c2, and c3corresponding to the three types of video signals in response to arecording mode selection signal k, supplies the selected one to arecording head (111) through a recording circuit (15310), and recordsthe signal on a longitudinal track on a magnetic tape. FIG. 36 shows thewaveform of a signal of a recording system according to the firstembodiment of the present invention. The waveform of a signal e readfrom the magnetic tape by a reproducing head (11) is shaped by areproducing circuit (15314) and converted into a pulse signal f. In afrequency discrimination circuit (15313), a plurality of frequencycomponent pulse signals g1 and g2 included in a reproduced controlsignal are discriminated and output, and a frame pulse signal g3 isgenerated and output. The frequencies of the signals g1 and g2frequency-discriminated at a normal tape speed are 120 Hz and 60 Hz,respectively with respect to the first video signal, 200 Hz and 50 Hz,respectively, with respect to the second video signal, and about 180 Hz(3 times 59.94 Hz) and 59.94 Hz, respectively, with respect to the thirdvideo signal. In a comparison circuit (15312), the ratio of thefrequency of the signal g1 to the frequency of the signal g2 iscalculated. More specifically, in a normal-speed reproducing mode,120/60=2 is obtained with respect to the first video signal, 200/50=4 isobtained with respect to the second video signal, and 59.94×3/59.94=3 isobtained with respect to the third video signal. These ratios offrequencies are constant even in a special reproducing mode. Forexample, in a double-speed reproducing mode, since a tape speed is twicethe normal speed, the frequency of a signal included in a control signalrecorded on a longitudinal track uniformly becomes twice. Thefrequencies of the signals g1 and g2 frequency-discriminated withrespect to the first video signal become 240 Hz and 120 Hz,respectively. Therefore, an output h from the comparison circuit (15312)becomes 240/120=2, and this value coincides with the value obtained at anormal tape speed. Similarly, with respect to each of the second andthird video signals, even when a tape speed in a reproducing operationchanges, the output h from the comparison circuit (15312) coincides withthe value obtained at a normal tape speed. The output from thecomparison circuit (15312) is input to an identification circuit(15311), so that a recorded video signal standard can be determined bychecking whether the input signal is 2, 3, or 4. A discrimination signali from the identification circuit (15311) is transferred to a systemcontrol circuit (not shown) as a recording mode signal of the system,and a mechanism/control system and a signal processing circuit are setin an operation mode matched with a predetermined video signal.

FIG. 37 shows the second embodiment of a TC/CTL/CUErecording/reproducing circuit according to the present invention. Inthis embodiment, with respect to two types of video signals, anidentification pulse having a frequency which is the greatest commonmeasure of the frame frequencies of the video signals is superposed on aframe pulse and recorded on a control track, and a recorded video signalis determined in a reproducing operation on the basis of the superposedidentification pulse and a frame pulse. FIG. 38 shows the waveforms ofthe main pulses in FIG. 37. This embodiment will be described below withreference to FIGS. 37 and 38. An output signal j from an oscillationcircuit (15318) is frequency-divided by a frequency division circuit(15319) into a signal k1 having a frame frequency of 30 Hz of the firstvideo signal, a signal k2 having a frame frequency of 25 Hz of thesecond video signal, and a signal k3 having a frequency of 5 Hz forgenerating a mode identification signal having a frequency which is thegreatest common measure of these frame frequencies. One of the two framesignals k1 and k2 is selected by a mode selection signal k in aselection circuit (15321) as the frame signal of a recorded videosignal. On the other hand, the signal k3 is converted by a pulsegeneration circuit (15320) into a mode identification pulse signal shownin (k4) in FIG. 38. The selected frame signal 1 and the modeidentification pulse k4 are added to each other by an adding circuit(15322) to generate a control signal m. The control signal m is recordedon a longitudinal control track on a magnetic tape through a recordingcircuit (5323) and a magnetic head 11. (e) in FIG. 38 shows a controlsignal corresponding to two video signals. Due to the relative phaserelationship between a frame frequency and a mode identification pulse,a video mode can be identified even when a tape speed changes. Areproduced signal read from the magnetic head 11 is subjected towaveshaping and identification by a reproducing circuit (15326) andconverted into a control pulse signal o. The control pulse signal o isinput to a counting circuit (15327) and a pulse detection circuit(5327), the leading edge of the control pulse signal o is counted, andthe mode identification pulse signal k4 in FIG. 38 is extracted, therebyresetting the counting circuit (15327). A count value q obtained at anormal reproducing speed becomes 5 and 6 with respect to the two videosignals, and the video signals are identified by an identificationcircuit (15323). In a special reproducing operation, the count value ofthe counting circuit also becomes 5 and 6 with respect to the videosignals, and the video signals can be identified.

FIG. 39 shows the third embodiment of a TC/CTL/CUE recording/reproducingcircuit 153 according to the present invention. In this embodiment, thefollowing method is employed. That is, pulse strings having thedifferent numbers of pulses are superposed on frame signals havingdifferent frequencies, respectively, and the mode of a video signal isidentified on the basis of the number of pulses. FIG. 40 shows mainpulse strings in FIG. 39. This embodiment will be described below withreference to FIGS. 39 and 40. An output signal j from an oscillationcircuit (15330) is input to a frequency division circuit (15331) togenerate a first video frame signal k1 having a frequency of 30 Hz, asecond video frame signal k2 having a frequency of 25 Hz, and amultiplexed pulse signal k5 having a frequency of 60 Hz. One of the twoframe signals k1 and k2 is selected by a mode selection signal k in aselection circuit (15332) as a frame signal 1 of a recorded videosignal.

The frame signal 1 is caused by a gate generation circuit (15333) togenerate a gate pulse shown in (s) in FIG. 40 and corresponding to thefirst and second frame signals selected by the mode selection signal k,using the trailing edge of the frame signal as a reference. The pulsewidth of a gate pulse s corresponds to the two pulses and four pulses ofthe multiplexed pulse k5 with respect second frame and second framesignals. The multiplexed pulse k5 is intermittently selected by the gatepulse S in the gate circuit (15334) to generate a mode identificationpulse string t. In addition, the frame signal 1 and the modeidentification pulse string t are multiplexed with each other by anadding circuit (15335) to a t control signal u. The t control signal uis recorded on a tape longitudinal control track through a recordingcircuit (15336) and a magnetic head 11. As is apparent from the controlsignal waveform in (u) in FIG. 40, when the pulses of the modeidentification pulse string multiplexed with the frame signal arecounted, a reproduced video signal can be specified by the count valueregardless of a tape speed. A reproduced signal v read from the magnetichead 11 is subjected to waveshaping and identification by a reproducingcircuit (15337) to reproduce a control pulse w. As in a recordingsystem, a gate pulse x used for extracting a multiplexed pulse from thecontrol pulse w is generated by a gate generation circuit (15338), and amultiplexed pulse y is extracted from the control pulse w by a gatecircuit (15339). Multiplexed pulses are counted by a counting circuit.If a count value z is 2, the first video signal is determined by anidentification circuit 15341; if the count value z is 4, the secondvideo signal is determined. In addition, an identification signal istransferred to a system control circuit (not shown).

In this manner, according to the present invention, as a recording modeidentification scheme for different video signal schemes, a recordingmode identification signal is recorded on a longitudinal track in a taperunning direction. For this reason, in special reproducing operationmode such as a slow reproducing operation or a high-speed reproducingoperation performed, erroneous determination due to omissions of signalscaused by recording data on helical tracks is not performed, and anunstable operation is not performed. In addition, since a control signalobtained by superposing a frame signal on an identification signalhaving a relatively simple frequency or a phase relationship with theframe signal is recorded, not only the recording mode identificationscheme can be realized by a simple circuit arrangement, but also anidentification signal can be easily determined. For this reason, even ifa recording/reproducing state is degraded by damaging or wearing a tape,a recording mode can be stably determined. Therefore, a serious accidentsuch as damage to the VTR main body or destruction of software caused byan erroneous recording mode determination operation can be prevented,and stable recording/reproducing operations of video and audio signalscan be realized. In addition, since a scheme for performing a recordingoperation on a control track on the basis of a frame signal is used,continuity between a VTR using this scheme and a conventional VTR isensured, and the VTR using the scheme can be properly matched withconventional VTR peripheral equipment such as an editing machine or acamera.

A method of identifying a recording mode by properly processing aninformation signal in a video signal track or an AUDIO signal track willbe described below. More specifically, according to this embodiment,signals based on different standards are recorded on a recording mediumsuch that the recording rates of the signals are set to be equal to eachother, and segment signals constituted by sync blocks to which syncsignals for obtaining timing synchronization in a signal reproducingoperation are added are used. The plurality of sync signals are presentin a predetermined period immediately before the start sync block ofeach segment signal, and the number of sync signals present in thepredetermined period immediately before each start sync block is changedin accordance with different standards.

As another embodiment, the phase of a sync signal present in thepredetermined period immediately before the start sync block of each ofthe above segment signals is changed in accordance with differentstandards within the predetermined period.

As another method, the following method is used. That is, a patternhaving a predetermined frequency in a reproducing operation is presentin a predetermined period immediately before the start sync block ofeach segment signal, and the frequency of the pattern is changed inaccordance with different standards. As another embodiment, thefollowing embodiment will be described. That is, signals based ondifferent standards are recorded on a medium at recording ratesrespectively inherent in the standards, and segment signals constitutedby a plurality of sync blocks to which sync signals for obtaining timingsynchronization in a signal reproducing operation are added are used. Apattern which has a predetermined frequency in the reproducing operationis formed in a predetermined period immediately before the start syncblock of each segment signal, and different standards are identified bya frequency component obtained by reproducing the pattern portion.

At this time, the pattern which has a predetermined frequency in areproducing operation and is formed in the predetermined periodimmediately before the start sync block of each segment signal is apattern for bit synchronization or part thereof.

The following method is also used. In a recording/reproducing apparatuswhich can cope with multi-standards, segment signals constituted by aplurality of sync blocks to which sync signals for obtaining timingsynchronization in a signal reproducing operation are added are used,and the sync signal pattern is changed in accordance with the standards.

As still another embodiment, identification can be performed by changinga channel coding scheme in accordance with the standards.

When each of the identification methods is used, only when all theplurality of changes or setting elements of the recording/reproducingapparatus which are required for causing the recording/reproducing tocope with standards are performed in accurate states with respect to thestandards, it is determined that the recording/reproducing is set tocope with the standards.

The plurality of changes or setting elements are characterized byincluding at least information representing the state of a switch forchanging a signal processing circuit, the type of a reference signalrequired for recording/reproducing a signal, and physical deformationadded to a recording medium itself or the case of the recording mediumor recorded standards given by an information recording medium added tothe recording medium.

In the plurality of HDTV standards, the different numbers of activelines, different frame frequencies, different sampling rates, and thelike are respectively set. For this reason, in order to prevent arecording/reproducing system from being complicated, a countermeasurefor performing a recording/reproducing operation using the samerecording rate and the same format by implementing a signal processingunit is considered. In such a case, when a signal is reproduced, datacan be identified in any standard. The following embodiment is relatedto a scheme for reproducing signals of different standards recorded inthe same format at the same recording rate to identify the standards.

FIG. 41 shows the arrangement of a segment signal according to thisembodiment. As shown in FIG. 41, in this segment signal, before a firstblock 4109 of a digital information signal, a portion is arranged inwhich 5 sync signals 4102 to 4106 (=M) are continuously concentrated andarranged not to continue a sync signal 4108 (n bits) added to the startportion of the first block 4109. Note that the sync signals 4102 to 4106need not be necessarily continued, and the sync signals 4102 to 4106 maybe arranged with intervals. Before the portion in which the sync signals4102 to 4106 are concentrated and arranged, a locking signal 4101 forreproducing a bit clock is arranged. Although any signal except for async signal may be used as a signal 4107 arranged between the syncsignal group and the first block 4109, the same signal as the lockingsignal 4101 for reproducing a bit clock is preferably used as the signal4107 in consideration of synchronization of the bit clock.

FIG. 42 is a block diagram showing the arrangement of a standardidentification circuit according to this embodiment. Although eachelement is operated with reference to a bit clock reproduced from, e.g.,a reproduced signal, by a PLL circuit or the like, a bit clockreproducing system and a bit clock supply system are omitted in FIG. 42.

Referring to FIG. 42, the segment signal shown in FIG. 41 is input to aninput terminal 4201. This segment signal is serially received by ann-bit shift register 4203. The n bits of an output from the n-bit shiftregister 4202 are compared with corresponding bits of an n-bit syncsignal pattern prestored in a sync signal detection unit 4203. When allthe n bits coincide with the corresponding bits, a sync signal detectionpulse is output. The sync signal detection pulse is supplied to a gategeneration unit 4204 and a counting unit 4205.

When the gate generator 4204 receives the sync signal detection pulse,the gate generator 4204 generates a gate pulse having a predeterminedwidth to supply it to the counting unit 4205. The counting unit 4205counts sync signal detection pulses input while the gate pulse issupplied, thereby outputting a count value. An identification unit 4206outputs an identification pulse when the count value satisfies acondition with respect to a set value N. This set value N is set to bedifferent values in accordance with the standards. For example, whenthree types of standards are used, three values N1, N2, and N3 areprepared for the standard 1, 2, and 3, respectively. The number M ofsync signals in the concentrated and arranged sync signal groupsatisfies a condition N≦M with respect to the set value N, and isrecorded to have different values corresponding to the standards. Forexample, when three types of standards are used, three values M1, M2,and M3 are prepared for the standards 1, 2, and 3, respectively. Forexample, assuming that these values are set to satisfy a condition 2 sN1 s M1<N2 s M2<N3 s M3, if a count value C of the counting unitsatisfies a condition N1 s C s M1, an identification pulse representingthe standard 1 is output; if the count value C satisfies a condition N2s C s M2, an identification pulse representing the standard 2 is output;and if the count value C satisfies a condition N3 s C s M3, anidentification pulse representing the standard 3 is output. In thismanner, the three types of standards can be identified. In this case,the set value N of the count value is set to be smaller than the numberM of concentrated and arranged sync signals because all the concentratedand arranged sync signals are not always detected due to an error. Thenumber M of the concentrated and arranged sync signals and the set valueN of the count value are preferably selected from optimal values inaccordance with systems.

FIG. 43 shows an embodiment of another segment signal. (a) in FIG. 43shows a segment pulse representing a start portion of the segmentsignal, and (b) in FIG. 43 shows the start portion of the segmentsignal. Before a first block 4306 of a digital information signal, twoareas 4302 and 4303 in which a sync signal group is arranged not tocontinue a sync signal 4305 (consisting of n bits) added to the startportion of the first block 4306 are continuously arranged. Note that theareas 4302 and 4303 need not be necessarily continued, and the areas4302 and 4303 may be arranged with an interval. A locking signal 4301for reproducing a bit clock is arranged before the areas 4302 and 4303.Although any signal except for a sync signal may be used as a signal4304 arranged between the area in which the sync signal group isarranged and the first block 9, when synchronization of the bit clock isconsidered, the same signal as the locking signal 4301 for reproducing abit clock is preferably used as the signal 4304. (c) and (d) in FIG. 43show gate pulses for respectively detecting the two areas 4302 and 4303in which the sync signal group is arranged, and the gate pulses areformed with reference of the segment pulse in (a) in FIG. 43.

Standards are identified in accordance with a specific area of the areas4302 and 4303 in which the sync signal group is arranged. In thisembodiment, since two areas are arranged in each of the areas 4302 and4303, a maximum of four types of standards can be identified. The numberof types of standards which can be identified can be increased/decreasedin accordance with the number of areas arranged in the areas 4302 and4303.

FIG. 44 is a block diagram showing the arrangement of the secondstandard identification circuit according to this embodiment. Althougheach element is operated with reference to a bit clock reproduced by,e.g., a reproduced signal PLL circuit, a bit clock reproducing systemand a bit clock supply system are omitted in FIG. 44.

Referring to FIG. 44, the segment signal shown in FIG. 43 is input to aninput terminal 4501. This segment signal is serially received by ann-bit shift register 4402. The n bits of an output from the n-bit shiftregister 4402 are compared with corresponding bits of an n-bit syncsignal pattern prestored in a sync signal detection unit 4403. When allthe n bits coincide with the corresponding bits, a sync signal detectionpulse is output. The sync signal detection pulse is supplied to a gategeneration unit 4404 and a counting unit 4405. When the gate generator4404 receives the sync signal detection pulse, the gate generator 4404generates a gate pulse having a predetermined width to supply it to thecounting unit 4405. The counting unit 4405 counts sync signal detectionpulses input while the gate pulse is supplied, and the counting unit4405 outputs a detection pulse of the sync signal group when the countvalue satisfies a condition with respect to a set value N. Assuming thatthe number of sync signals included in the sync signal group isrepresented by M, when the value N is set to satisfy a condition N<M,e.g., when the count value satisfies a condition N s C s M, anidentification pulse is output. In this case, the set value N of thecount value is set to be smaller than the number M of sync signalsincluded in the sync signal group because all the sync signals includedin the sync signal group are not always detected due to an error. Thenumber M of sync signals included in the sync signal group and the setvalue N of the count value are preferably selected from optimal valuesin accordance with systems. A detection pulse of the sync signal groupis supplied to a detection unit 1 (4506) and a detection unit 2 (4407).Detection gates respectively representing the areas 4302 and 4033 fordetecting the presence of the sync signal group are generated by adetection gate generation unit 4409 with reference to a segment pulseinput from an input terminal 4408, and the detection gates are suppliedto the detection unit 1 (4406) and the detection unit 2 (4407),respectively. Each of the detection unit 1 (4406) and the detection unit2 (4407) checks whether the sync signal group is present in acorresponding one of the areas, and each of the detection unit 1 (4406)and the detection unit 2 (4407) outputs "1" representing that the syncsignal group is present or "0" representing that the sync signal groupis absent to a corresponding one of output terminals 4410 and 4411. Acorresponding standard can be identified by decoding the 2-bit output.

In each of the above two embodiments, although a case wherein a syncsignal is used as an identification signal has been described, anidentification signal having a pattern different from a sync signal canbe used without any problem when a detection unit capable of detectingan identification signal pattern is arranged in place of a sync signaldetection unit in the above arrangement.

FIG. 45 shows an embodiment of another segment signal. (a) in FIG. 45shows the start portion of the segment signal. Before a first block 4505of a digital information signal, an area 4502 is formed in which apattern having a predetermined frequency in a reproducing operation isto be recorded. A locking signal 4501 for reproducing a bit clock isarranged before the area 4502. A signal 4503 arranged between the areain which the pattern which has a predetermined frequency in areproducing operation is recorded and the first block 4505 need not benecessarily arranged. Alternatively, when synchronization of the bitclock is considered, the same signal as the locking signal 4501 forreproducing a bit clock may be used as the signal 4503. (b) in FIG. 45shows a segment pulse representing the start portion of the segmentsignal. (c) in FIG. 45 shows a gate pulse for detecting the area 4502 inwhich the pattern having a predetermined frequency in a reproducingoperation is recorded, and the gate pulse is generated with reference ofthe segment pulse in (a) in FIG. 45. In the area 602 in which thepattern having a predetermined frequency in a reproducing operation isrecorded, the frequency is changed in accordance with standards, therebyidentifying the standards. For example, a repetition pattern "10" is setfor a standard 1, a repetition pattern "1100" is set for a standard 2,and a repetition pattern "11110000" is set for a standard 3. In thiscase, when a frequency obtained when the repetition pattern "10" of thestandard 1 is reproduced is represented by f, a frequency f/2 isobtained in the standard 2, and a frequency f/4 is obtained in thestandard 3. Therefore, the standards can be identified in accordancewith a reproduced frequency.

FIG. 46 is a block diagram showing the arrangement of the third standardidentification circuit according to this embodiment. A reproduced signalof a segment having the arrangement shown in (a) in FIG. 45 is input toan input terminal 4601. This reproduced signal is supplied to a gatecircuit 4602. Only identification pattern portion is extracted by thegate shown in (c) in FIG. 45 and generated by a gate generation unit4604 with reference to a segment pulse input from an input terminal4603, and the extracted identification pattern portion is supplied to anidentification unit 4605. The identification 4605 is constituted byfrequency detection units. In this case, in order to identify the abovethree types of standards, the identification unit 4605 is constituted bya detection unit (1) 4606 for detecting the frequency f, a detectionunit (2) 4607 for detecting the frequency f/2, and a detection unit (3)4608 for detecting the frequency f/4. When a detection unit whichoutputs a detection pulse is detected, the standards can be identified.Each detection unit may be constituted by, e.g., a band-pass filter anda level detection circuit.

A plurality of patterns which have different frequencies in areproducing operation are prepared. Referring to (a) in FIG. 45, whencombinations of patterns recorded in the area 4502 in which patterns areto be recorded correspond to the standards, the standards can beidentified in accordance with a combination of frequencies detected in areproducing operation. FIG. 47 is a block diagram showing thearrangement of an identification circuit used in this case. Thisidentification circuit has the same basic arrangement as that in FIG.46. FIG. 47 shows a case wherein two types of patterns, e.g., the aboverepetition patterns "10" and "1100", are prepared. When a frequencyobtained when the repetition pattern "10" is reproduced is representedby f, the identification unit 4605 is constituted by a detection unit(1) 4706 for detecting the frequency f and a detection unit (2) 4707 fordetecting a frequency f/2. For example, in the area 4502 (in (a) in FIG.45) in which patterns are to be recorded, only the repetition pattern"10" is recorded for the standard 1, only the repetition pattern "11100"is recorded for the standard 2, and both the repetition patterns "10"and "1100" are recorded for the standard 3. In this manner, when it ischecked whether a detection pulse or detection pulses are output fromonly the detection unit (1) 4706 for detecting the frequency f, only thedetection unit (2) 4707 for detecting the frequency f/2, or both thedetection unit (1) 4706 and the detection unit (2) 4707, the three typesof standards can be identified. That is, when a combination of thepresence/absence of detection pulses from the frequency detection unitsis decoded, the standards can be identified.

When a recording rate changes in accordance with standards, even whenthe same pattern is used, different frequencies are obtained in areproducing operation. For this reason, different patterns need not beprepared for the standards, respectively. When a detection unit fordetecting frequencies corresponding to the standards and exhibited by,e.g., a repetition pattern "10", in a representing operation due to thedifferences between the recording rates is arranged, the standards canbe identified. Since a pattern which has a single frequency in areproducing operation is generally used as a bit synchronizationpattern, a bit synchronization pattern portion or part thereof can alsobe used as a pattern for identifying the standards.

According to the present invention, when a tape is reproduced, arecorded standard is automatically identified. For this reason, a changein standard of a DVTR can be automatically performed. Sinceidentification is always performed at the start portion of a segment,even when a reproducing operation is started from the midway of thetape, and a standard of recorded data changes in the midway of the tape,the standard can be automatically identified. In addition, since a syncsignal or a pattern having a single frequency is used as anidentification signal, a signal arrangement and the arrangement of anidentification circuit are not complicated.

FIG. 48 is a block diagram for explaining an embodiment in which, when async signal for obtaining block synchronization is changed in accordancewith standards, and a tape recorded in a standard different from astandard set in a DVTR is reproduced, a reproduced image signal and areproduced audio signal are not output. In this case, a case whereinthree types of standards are used will be described. Note that only anarrangement different from that in FIG. 1 will be described in thiscase. When data is to be recorded on a tape, a sync signal 4801, 4802,or 4803 determined in correspondence with each standard is selected by aswitch 4804. When data is to be reproduced, a sync signal pattern 4805,4806, or 4807 is selected by a switch 4808 in accordance with thecorresponding standard which is originally recorded, so that a syncsignal can be detected. However, when a tape recorded in a standarddifferent from the standards set in the DVTR is reproduced, a syncsignal cannot be detected by a sync detection unit 134 because the syncsignal pattern selected by the switch 4808 is different from a recordedsync signal pattern. Therefore, since block synchronization is notobtained, data processing cannot be performed by a demodulation unit 135and a decode unit 136, no signal is supplied to video/audio outputunits, and a reproduced image signal and a reproduced audio signal arenot output.

It is checked that no sync signal is detected and no blocksynchronization is obtained regardless of inputting a reproduced signalto a sync signal detection unit, thereby causing an operator to knowthat a standard is erroneously set.

FIG. 49 is a block diagram for explaining an embodiment in which, when achannel coding is changed in accordance with standards, and a taperecorded in a standard different from a standard set in a DVTR isreproduced, a reproduced image signal and a reproduced audio signal arenot output. In this case, a case wherein three types of standards areused will be described. Note that, as in FIG. 48, only an arrangementdifferent from that in FIG. 1 will be described in this case. When datais to be recorded on a tape, a modulation circuit 4901, 4902, or 4903 ofchannel coding determined in correspondence with each standard isselected by a switch 4904. When data is to be reproduced, a demodulationcircuit 4905, 4906, or 4907 is selected by a switch 4808 in accordancewith the corresponding standard which is originally recorded, so thatdemodulation can be correctly performed. However, when a tape recordedin a standard different from the standards set in the DVTR isreproduced, demodulation is not correctly performed because thedemodulation circuit selected by the switch 4908 is different from thedemodulation circuit of recorded channel coding. Therefore, decodingcannot be started from data supplied to a decoder 136, and no signal issupplied to video/audio output units, and a reproduced image signal anda reproduced audio signal are not output.

It is checked that decoding cannot be performed from the data suppliedto the decoder 136 regardless of inputting a reproduced signal to ademodulation unit, thereby causing an operator to know that a standardis erroneously set.

According each of the above embodiments, when a tape recorded in astandard different from the standards set in a DVTR is reproduced, adisturbed image can be prevented from being output to a monitor, or anuncomfortable sound can be prevented from being output. In particular,while a program is transmitted, the disturbed image or uncomfortablesound are not directly transmitted. In addition, non-detection of a syncsignal or the state of decode addition is checked, thereby causing anoperator to know that the standard of the tape is different from thestandards set in the DVTR.

FIG. 50 is a block diagram showing an arrangement in which changes orthe states of setting elements required for causing a DVTR to correspondto each standard are managed and determined. Note that the arrangementin FIG. 50 can also be applied to the controller 132.

In this case, as the changes or setting elements, an A/D clockfrequency, the type of a frame pulse, identification information to beadded, switching of coding circuit, switching of decoding circuit,switching of a servo circuit, switching of a recording/reproducingcircuit, recorded standard information (cassette), and display are used.

Referring to FIG. 50, reference numerals 5001 to 5009 denote units fordetecting the changes or the states of setting elements and outputtingthe information of the states. An information management determinationunit 5010 receives pieces of information output from the stateinformation output units 5001 to 5009, selects required information inaccordance with mode information from a recording/reproducing modeoutput unit 5011, and outputs determination information representingwhether the overall DVTR can cope with a desired standard. As adetermination method, a method of determining that the overall DVTR cancope with the desired standard when all the pieces of state informationare correct with respect to the desired standard.

Determination information can be used for alarming, orchecking/resetting the changes or the states of setting elements.

According to the above embodiments, all the changes or the states ofsetting elements are managed, and it is determined that the overall DVTRcan cope with a desired standard when all the pieces of stateinformation are correct with respect to the desired standard. For thisreason, a tape recorded in a scheme which does not correspond to anystandard can be prevented from being formed. In addition, sinceprocessing is correctly performed in a reproducing operation, areproduced image can be prevented from being disturbed, or anuncomfortable sound can be prevented from being generated.

As further detailed contents of user data, e.g., the followings areknown. That is, recorded video data, the INDEX information of audiodata, a recording date, and a title are used. These information data areeffective in a retrieval operation. When data representing the type of alanguage, e.g., data CH1 representing English or data CH2 representingFrench, is recorded in each channel of an audio signal, this informationdata is effective for CH selection. Information data representing thetype of a source of recorded video/audio signals, e.g., signals directlyobtained from a camera, signals dubbed by another VTR, signals obtainedfrom telecine, or up-converted signals are effective to know the qualityof the signals. In an editing operation, the history of used video/audiosignals, e.g., a specific video signal in each library, date of a newssource, or the like are used. These information data can recordproduction processes. These information data can be easily input by keysbelonging to a VTR or an external personal computer using acommunication port.

A compressed image can be added to user data. For example, when therepresentative video data of recorded video data is added to the userdata, this video data is effective for a retrieval operation. In thiscase, 1-frame or 1-field data of input video data is received by amemory, and the data is compressed by a compression encoder to have adata amount suitable for a recording area. In addition, image data whichis externally compressed can be supplied through a port.

When not only data uniquely formed by a user but also data included in amachine itself for maintenance are directly and simultaneously writtenin a recording operation, these data is effective to form an optimalenvironment in a reproducing operation. As these data, e.g., themanufacture numbers, recording dates, and recording times of a VTR inuse, a scanner, and an external connector are used. In a VTR, sincethese data are managed by a microcomputer, the data are directly read.In external machines, data managed by the microcomputer of each machinemay be received by a communication port and written. When these data areautomatically written, efficiency increases.

When data representing a use state of a tape is written in advance, thedata is effective to know damage to the tape. As this data, the numberof times of use of the tape is used. When this data is read by apre-reproducing head, and the value of the data is updated and recorded,the number of times of partial pass of the tape can be known.

An adjusting signal can be recorded in place of user data. For example,when a signal for obtaining tracking information is recorded in advance,tracking can be accurately performed without using a CTL. In addition,when signals having different frequencies are arranged and recorded, andthe amplitude of a reproduced signal in a reproducing operation isexamined, a change in frequency characteristic can be known. This iseffective to estimate the wear of a head. When an automatic equalizationfunction is added, and a test pulse for the automatic equalizationfunction is recorded, more accurate equalization can be performed. Thesesignals are effectively added to the start portion of each track. Notethat the above adjusting signal is added to an adder 129 in parallel toa SYNC information generator 130, thereby recording the adjustingsignal.

As described above, in a cassette digital magnetic recording/reproducingapparatus according to the present invention, when image signals ofdifferent HDTV schemes are recorded/reproduced, and the mechanism,circuit, cassette tape, and the like of a VTR are commonly used,programs can be easily exchanged between Japan, the United States,Europe, and costs of machines or running costs can be reduced.

What is claimed is:
 1. A digital magnetic recording/reproducingapparatus for recording and reproducing digitally a high definitiontelevision (HDTV) signal in accordance with a first mode for recordingand reproducing a 1125/60-scheme HDTV signal representing a HDTV signalof 1125 lines per frame and 60 fields per second and a second mode forrecording and reproducing a 1250/50-scheme HDTV signal representing aHDTV signal of 1250 lines per frame and 50 fields per second,comprising:a rotary drum on which 16 recording heads and 16 reproducingheads are mounted; a rotary machine for rotating, in both the first modeand the second mode, the rotary drum at a rotation speed of 150revolutions per second in a recording operation, to record video data ona magnetic tape while forming eight helical tracks thereon everyhalf-revolution of the rotary drum, and rotating the rotary drum at arotation speed of 150 revolutions per second in a reproducing operation,to reproduce the video data by reading the eight helical tracks on themagnetic tape every half-revolution of the rotary drum; and a recordinghead control unit for controlling the recording heads to form, in therecording operation according to the first mode, 40 helical tracks onthe magnetic tape every 2.5 revolutions of the rotary drum and recordvideo data of one field thereon, the recording head control unitcontrolling the recording heads to form, in the recording operationaccording to the second mode, 48 helical tracks on the magnetic tapeevery 3 revolutions of the rotary drum to record video data of one fieldthereon; wherein the recording head control unit includes a controllerfor controlling the recording heads to record video data on the magnetictape by dividing a video data signal into 8 channels in the recordingoperation according to each of the first mode and the second mode,recording error correction code blocks of video data within 5 trackscorresponding to one channel and one field in the recording operationaccording to the first mode, and recording correction code blocks ofvideo data within 6 tracks corresponding to one channel and one field inthe recording operation according to the second mode.
 2. The apparatusaccording to claim 1, wherein the recording head control unit includes acontroller for controlling the recording heads to record, on themagnetic tape, identification information representing that one of thefirst mode and the second mode has been used in the recording operation,and the reproducing head control unit includes a controller forcontrolling the reproducing heads to reproduce the identificationinformation recorded on the magnetic tape.
 3. The apparatus according toclaim 1, wherein the recording head control unit includes a controllerfor controlling the recording heads to record audio signals of 10channels on the magnetic tape in the recording operation according tothe first mode, and audio signals of 12 channels in the recordingoperation according to the second mode.
 4. A method of recording andreproducing digitally a high definition television (HDTV) signal inaccordance with a first mode for recording and reproducing a 1125/60scheme HDTV signal representing a HDTV signal of 1125 lines per frameand 60 fields per second and a second mode for recording and reproducinga 1250/50-scheme HDTV signal representing a HDTV signal representing aHDTV signal of 1250 lines per frame and 50 fields per second, comprisingthe steps of:in both the first mode and the second mode, rotating arotary drum on which 16 recording heads are mounted at a rotation speedof 150 revolutions per second in a recording operation, to record videodata on a magnetic tape while forming eight helical tracks thereon everyhalf-revolution of the rotary drum, and rotating a rotary drum on which16 reproducing heads are mounted at a rotation speed of 150 revolutionsper second in a reproducing operation, to reproduce the video data byreading the eight helical tracks on the magnetic tape everyhalf-revolution of the rotary drum; in the recording operation accordingto the first mode, forming 40 helical tracks on the magnetic tape every2.5 revolutions of the rotary drum to record video data of one fieldthereon; in the recording operation according to the second mode,forming 48 helical tracks on the magnetic tape every 3 revolutions ofthe rotary drum to record video data of one field thereon; in therecording operation according to the second mode, adding recording datato make an amount of information per 8 helical tracks in the second modecoincide with that per 8 helical tracks in the first mode; and recordingvideo data on the magnetic tape by dividing a video data signal into 8channels in the recording operation according to each of the first modeand the second mode, recording error correction code blocks of videodata within 5 tracks corresponding to one channel and one field in therecording operation according to the first mode and recording errorcorrection code blocks of video data within 6 tracks corresponding toone channel and one field in the recording operation according to thesecond mode.
 5. The method according to claim 4, further including thesteps of recording, on the magnetic tape, identification informationrepresenting that one of the first mode and the second mode has beenused in the recording operation, and reproducing the identificationinformation recorded on the magnetic tape.
 6. The method according toclaim 4, further including the steps of recording audio signals of 10channels on the magnetic tape in the recording operation according tothe first mode, and audio signals of 12 channels in the recordingoperation according to the second mode.